Process of increasing the raising power of dried yeast.



UNITED 1;

rn'rrm mums nrnmoitonmavna, or SLNDE, Gamma rnocnss or INCBEASINQ-m. aars'nm or mum) Ymsr,

1,oe1,7'o0. Io Iirawing.

To all whom it may concern: I i

Be it known 'that I, PETER Dmomon Hmmon OHLHAVER, a subject of the Emperor of Germany, residing at Sande, Germany, have invented certain new and useful Improvements in Processes of Increasing the Raising Power of Dried 'Ye'ast, of which the followlng is a specification.

This invention relates to a PI'OCGSS of treating dried yeast with moisture laden air prior to using it, and has for its object to increase the raising and fermenting power of the dried yeast to its maximum amount. I Fresh yeast can be dried without injuring the activity of the yeast organisms'by observing certain precautions and the active properties of the yeast can be preserved in 'the dried state for a considerable time.

There is however a drawback to this state in that the .raising power of the yeast is inversely proportional to the amount of drying which it undergoes, and with progressive drying therefore a diminishin degree of ralsing'and fermenting power 1s forthcoming. By the present invention the lost raising and fermenting power of. the dry yeast is restored to its original strength, or it may even be increased beyond its original strength. I

The organisms of the yeast are albuminous bodies which can only develop their full activity when in a hydrated condition that is to say, when molecules of water are combined with them. During the drying process and particularly during an intense or prolonged drying process not only 15 the water within the yeast cell evaporated, but thenvater molecules are also withdrawn from the hydrated organisms of the yeast by which the activity of such organisms is correspondingly paralyzed. In order to restore to the organisms of the dry yeast then full strength, an opportunity must be aflorded to the dry yeast to re-attach to its organisms the molecules of water which have been taken away by drying. This is accomactivity. The time required in which to hydrate these organisms depends essentially .on the degree of humidity of the air. For

example, 10 grams of a dry yeast had a raising power of 2240 ccm. In order to premes-e; Letters Patent.

longer time i t was further dried and in-so doing 1ts, -ra1s1ng power was reduced to 1160 com. .This same much-dried yeast was then exposed for about 43 hours in thin layers to' Patented Mar. 26, 1912. Application messa es: 24, 1911. Serial No. 845,828.

serve the life o f 't-his dry yeast fora stillatmospheric air, the air used may advantageously be saturated with moisture artificially. The full raising power of the yeast canthusbe imparted to it in a'much shorter time. For instance if the dry yeast is placed in a closed receptacle along with a damp cloth, but out of contact with same, the air in the receptacle will quickly become'saturated by reason of its taking up the moisture. from the cloth and the absorption of water by the yeast organisms will be accomplished in a correspondingly shorter time.

.The advantageous absorption of the vaporous moisture by the yeast appears to be due to a process of respiration which is set up. Neither putting the yeast in direct contact with water, or dissolving it in water, has the same eifect owing to the fact that neither course brings about the respiration required, or at least only to a very small extent. It is necessary that this absorption process for increasing the power of the yeast should be applied only a little while before the dry yeast is intended to be used, as after taking up the moisture the yeast will not keep very long; there wouldappea-r to be an inter-molecular respiration owin to the amount of moisture present and this gradually destroys the organisms of the yeast.

What I claim as my invention and desire to secure by Letters Patent is I 1-. The herein described process of increasing the raising power'of dried yeast, which consists in subjecting such yeast to the action of aqueous vapor for su'fii'cient time to cause re-hydration of the dried yeast organisms.

2. The hereindescribed process of increasing the raising power of dried yeast, which consists in exposingsuc'h yeast to the action of moist air for su'flicient timeto cause rehydration of the dried'yeast organisms.

3. The herein described process of increasing the raising power of dried yeast, which consists in exposing such yeast in thin layers to the actionof moist atmospheric air for sufiicient time to cause re-hydrat'ron;- f the consists inex'posing such yeast in thin layers dried yeast organisms. i. to. the action of air artificially saturated I 4. T e herein described rocess of increaswith moisture for sufiicient time to cause reing the raising power of ried yeast, which .hydration'of the dried yeast organisms.

5 consists in exposing such yeast to the action In testimony whereof I have aflixed my 15 of air artificially saturated with moisture slgnature in presence of two witnesses.

for suificient time to cause re-hydrati'on of PETER DIEDRIGH HINRIGH oumm'm the dried yeast organisms. Witnesses: 5. The herein described recess of increas- ERNEST H. L. MUMMENHOFF,

10 ing the raising power of ried yeast, which IDA Cmus'r. Humma gn. s 

